Pick-off head for sorting machine

ABSTRACT

A pick-off head for a machine for sorting cards or the like which uses subatmospheric pressure to pull the bottom card from its adjacent card to effect a separation of the two cards, and a mechanical thickness gauging device to insure singular lateral movement of the bottom card relative to its adjacent card. The bottom card is distorted by the subatmospheric pressure to remove its central region from contact with the adjacent card, but if static or other conditions prevent such separation, the thickness gauging device physically bars the second card from moving with the first.

United States Patent Brown et al.

[151 3,680,855 [451 Aug. 1,1972

[54] I PICK-OFF HEAD FOR SORTING MACHINE [72] inventors: Robert G. Brown; John R. Sorrells; Joseph E. Trent, all of Washington, DC.

[73] Assignee: B. H. Bunn Company, Chicago, Ill.

[22] Filedi June 29, 1970 [21] A pl. No.: 50,418

52 us. Cl ..-.....271/41 51 Int. Cl. ..B65h 1/06 53 Field of Search ...271/26 E, 29,41, 32, 27,44 A

[56] References Cited UNITED STATES PATENTS 2,827,290 3/1958 Dixon ..271/44 A 3,312,464- 4/1967 Rehm ..27l/26E 1/1919 Milmoe etal ..271/41 7/1968 Jaatinen ..27l/27 Primary Examiner-Richard E. Aegerter Attorney-Davis, Lucas, Brewer & Brugman [5 7] ABSTRACT A pick-off head for a machine for sorting cards or the like which uses subatmospheric pressure to'pull the bottom card from its adjacent card to effect a separation of the two cards, and a mechanical thickness gauging device to insure singular lateral movement of the bottom card relative to its adjacent card. The bottom card isdistorte'd by the subatmospheric pressure to remove its central region from contact with the adjacent card, but if static or other conditions prevent such separation, the thickness gauging device physically bars the second card from moving with the first.

5 Claims, 6 Drawing Figures PICK-OFF HEAD FOR SORTING MACHINE This invention relates to a pick-off head for a sorting machine and particularly to an improvement in the singulation means used therein.

In machines for processing card-like sheets supplied to the machines in stacks, it is necessary to handle the sheets from the stack one at a time. One such means is disclosed in U. S. Pat. No. 3,420,368 to Rosenberg et al., dated Jan. 7, 1969. In the Rosenberg et al., form, the means comprises a table on which the material to be sorted is stacked on edge, with a spring-pressed plate urging the stack continuously against a vertical abutment. An intermittent drive is imparted to the material by a rotating cam-shaped wheel which frictionally engages the end piece of the material and moves it sideways from the stack into the first stage of the materialprocessing machine. The spring-pressed plate is disposed parallel with the end piece and hence the latter piece is in complete surface-to-surface contact with the next piece in the stack.

It hasbeen found, in the Rosenberg et al., form, that several factors are present which decrease the effectiveness'of such mechanisms to pick off cards or the like, one at a time, from a stack of cards. Thus static electricity may cause two cards to stick together and move asone through the subsequent processing of the cards. At times a sticky substance may find its way between two cards and again cause two cards to be processed simultaneously instead of singly. It may also be found that if sufficient pressure is exerted upon the stack to ensure the proper placement of the bottom card against the reference plane or vertical abutment from which it is to be picked off for processing, such pressure. creates too much friction between the foremost card and its adjacent card for the pick-off mechanism to slide the bottom card laterally off the stack- It is an object of this invention to provide a means for facilitating the separation of the foremast card from a stack of cards to promote easy movement of the foremost card sideways from the stack for subsequent processing.

Another object of this invention is to provide a singulation device for cards which are to be separated from a stack of such cards, said device providing a gate large enough for only one card to pass therethrough, with means ahead of the gate for effecting a physical separation between the said one card and its adjacent card.

As a more specific object this invention has within its purview the provision of a means for producing a shape in the foremost card of a stack of such cards which is different from the shape of the card adjacent to the foremost card to effect a separation between said cards, whereby to facilitate subsequent relative lateral movement between the foremost and adjacent cards.

These and other objects of this invention will become apparent from the following detailed description of a preferred embodiment of the invention when taken together with the accompanying drawings in which:

FIG. 1 is a plan view of the pick-off mechanism of this invention;

FIG. 2 is a front elevational view in section of the mechanism of FIG. 1, the section being taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary plan view of the mechanism of FIG. 1 showing the shape and position of a card moved by the mechanism;

FIG. 4 is a side elevational view of the mechanism taken along line 44 of FIG. 2;

FIG. 5 is a side elevational view, in section, of the mechanism taken along line 5-5 of FIG. 2; and

FIG. 6 is a still further enlarged and fragmentary side elevational view, in section, of the drive portion of the mechanism taken along line 66 of FIG. 3.

The pick-off means of this invention is best adapted for use with stacks of relatively stiff material such as cardboard or the like. It is especially well suited for use in singulating covers for paperback books, wherein such covers are torn off the books and returned, in lieu of the entire book, to the publisher for determination of refunds to the bookseller, or other data processing. Essentially, the present pick-off means provides a chamber behind the pick-off reference plane in which chamber is located the friction drive for moving the covers singly laterally of the stack. The drive is comprised of a pair of cams which periodically protrude through openings in the plate defining the reference plane to engage and impel sideways the foremost cover of the stack. The chamber is subjected to subatmospheric pressure so that the foremost cover is pushed against the openings by the external atmospheric pressure. However, an abutment is provided on the reference plane plate to one side of the openings so that the cover is bowed when it is pushed against the openings. The cover immediately adjacent the foremost cover, however, is not bowed because it is shielded from the subatmospheric pressure by the foremost cover. Thus the foremost cover is separated from its adjacent cover despite any static electrical charge that may tend to hold them together, or the presence of a small quantity of adhesive accidentally placed between them. An adjustable resilient gate then provides a final singulation meansthrough which only one cover can pass at a time. The resilient gate has two rates of resilience, a soft rate for yielding under the pressure of cards considered acceptable, and a stiff rate for resisting the lateral movement of a second card which may be adhered to the first.

Referring now to the drawings for a detailed description of the invention, the pick-off device of this invention may be mounted on a base-plate 10 which may be the top of a table or a cabinet. The pick-off device itself, in the form illustrated, is comprised of a housing 11 mounted on plate 10 and defining a chamber 12 which is in communication with a conduit 13 connected to a device of known construction (not shown) designed to produce subatmospheric pressure in said conduit 13 and chamber 12. The front vertical wall 14 of housing 1 l is disposed substantially at right angles to the surface of base plate 10 and is designed to act as an abutment for a stack 15 of the cardboard sheets, such as paperback covers, to be processed one at a time by sorting and data processing equipment located to the left of housing 11 as viewed in FIG. 1, but not shown herein since it forms no part of the present invention.

The cardboard sheets making up stack 15 may be substantially rectangular in form having at least one straight reference edge 16 for data processing by which it is supported upon the surface of base plate 10. The stack is urged against front vertical wall 14 by a pressure plate 17 bearing against the front end cover 18 of the stack 15. Pressure plate 17, in turn, is urged continuously toward front vertical wall 14 by any suitable resilient means such as a tension spring 19 (FIG. 5) preferably disposed below plate and connected between an abutment 20 secured to a plate 10 and'to a guide 21 secured to a handle 22 on a pressure plate 17.

Said guide 21 extends through a slot 23 in plate 10 and is guided thereby.

Plate 17 is maintained in a predetermined vertical plane by guide 21, said plane being substantially at right angles to the longitudinal center line of the stack such that plate 17 exerts a substantially uniform pressure along the entire front cover 18 contacted thereby. Plate 17 also is disposed substantially parallel with the front vertical wall 14 of housing 11 so that substantially uniform pressure is transmitted through the stack to the rearmost or foremost cover 24 of the stack.

Lateral movement of the foremost cover 24 is effected by a pair of spaced cams 25, 26 which are driven from a central continuously rotating shaft 27 through a lost motion drive comprising a pin 28 disposed between the ends of a sector 29 secured to said shaft 27. The reason for the lost motion connection will be made apparent hereinafter.

As shown more clearly in FIG. 6, cams 25 and 26 are preferable made from an elastomeric material such as polyurethane appropriately molded to have a sector 30 or cylindrical .contour adapted frictionally to engage and propel the foremost cover 24 laterally of the stack 15, and a relief or dwell sector 31 opposite the drive sector 30. The two sectors in the form illustrated may each encompass approximately 180 of the periphery of a cam. Said cams 25 and 26 are mounted on a hub 32 freely rotable on shaft 27 through antifriction bearings 33. Although shaft 27 is disposed within housing 11, contact between cams 25 and 26 on the one hand and the foremost cover 24 on the other is established through openings 34 and 35 formed in front vertical wall 14 of housing 11 which are aligned with cams 25 and 26 so that the cylindrical drive sector 30 of each cam may protrude through its adjacent opening 34 or 35, as the case may be, into contact with said cover 24.

When a cover 24 is moved by the drive cam sectors 30 laterally to the left as viewed in FIG. 1, it is brought between a pair of drive rollers 36, 37, the peripheral speed of which is greater than the linear velocity of the cover 24 when moved by sectors 30, such that said cams 25 and 26 are accelerated by the cover 24 to the speed dictated by the drive rollers 35,35. The lost motion connection between the cams and their drive shaft 27, however, permits the cams to be accelerated for the length of time that the cams are in contact with a cover 24. Once the cover passes the cams, said cams are free to decelerate to the speed of said shaft 27.

As stated previously, the interior of housing 11 is at subatmospheric pressure such that card 24, which is adjacent to the openings 34 and 35, is pushed against said openings by the atmospheric pressure outside housing 11 and effectively covers said openings during the time the dwell sector 31 is rotating past said openings. This differential pressure across the foremost card 24 is utilized to establish a separation between it and its adjacent card in the following manner:

A vertical abutment 38, preferable made of low friction material such as nylon or polytetrafluoroethylene is secured to front vertical wall-14 a short distance to the left, as viewed in FIG. 1, from the right hand edge of the stack 15. Abutment 38 preferably has a rounded contour to provide, in effect, a line contact with card 24. Said abutment, as may be apparent from FIG. 1, causes the covers in the stack to assume an angular relation with respect to the surface of wall 14. This position is shown in connection with the penultimate cover 39, and, inasmuch as the foremost cover 24 extends over the openings 34 and 35 in wall 14 so as to, in effect, close said openings, said penultimate cover 39 is not subjected to any differential pressure on its opposite sides. Cover 39, therefore, assumes a flat planar position. The foremost cover 24, however, being drawn against the openings 34, 35 by the differential pressure acting on the cover, is bowed toward wall 14 by the presence of abutment 38, thereby establishing a separation between cover 24 and its adjacent cover 39. This separation is effective to reduce the forces of friction, or adhesion, between foremost cover 24 and its adjacent cover 39 and thus promotes the sliding of foremost cover 24 relative to said adjacent cover 39.

Despite the fact that abutment 38, combined with the differential in atmospheric pressure across the foremost cover 24, causes a separation between the foremost cover and its adjacent cover 39, there is still sufficient friction between the contacting ends of the said two covers to make it possible for both to be moved laterally by the cams 25, 26 when the movement of only the foremost cover 24 is desired. To insure proper singulation of the covers as they move off the foremost of the stack, the device shown generally at 40 is provided. Said device is comprised of a vertical plate 41 disposed at right angles to pressure plate 17 and adapted to function as an abutment for the left hand edges, as viewed in FIG. 1, of the covers in stack 15. Said plate 41 is secured to a slide 42 which has a rectangular groove 43 formed in the under surface thereof in which is received a guide 44 fixed to the upper surface of base plate 10. Plate 41 may be moved toward or away from front vertical wall 14 by an adjustment screw 45, and its position, once determined, may be fixed by a set screw 46.

The end of plate 41 nearest the front vertical wall 14 is provided with a substantially rectangular flat spring 47 which is held against plate 41 by a rigid back-up plate and the rectangular flat spring 47. The end of back-up plate 48 adjacent to front vertical wall 14 is curved as at 50 and the edge 51 of the curved end 50 is spaced from the rectangular flat spring 47 a distance which is such that the latter may flex to a limited extent in the direction of edge 51. The edge 52 of rectangular spring 47 is parallel to the outer surface of front vertical wall 14 and is spaced from there a distance slightly greater than the thickness of a cover in stack 15 to form a gate for individual covers. Thus one cover may be moved to the left as viewed in FIGS. 1 and 3 by the earns 25 and 26 through the space or gate formed between rectangular spring 47 and front vertical wall 14, but if two such covers tend to move through said space, the second will strike rectangular spring 47 and will be restrained from moving with the foremost cover in this stack. The width of the opening or gate between spring 47 and wall 14 may be adjusted by appropriately manipulating adjustment screw 45 after said screw 46 has been loosened. Minor differences in thickness of the covers are accommodated by a flexing of spring 47 until said spring strikes back-up plate 48.

In the event that the adhesion between the foremost cover 24 and its adjacent cover 39 is such that neither the differential in atmospheric pressure on the foremost cover nor the rectangular spring 47 can break it, said rectangular spring 47 will yield sufficiently to allow the double cover to pass through, but in the process the second cover, that is, the adjacent cover 39, will be visibly cut or scarred by the spring and the double cover may later be visually detected and manually separated from those processed. The passage of a double thickness cover, or a double cover, causes a deflection of both spring 47 and its back-up plate 48, but the deflection rate of the two is less per unit force than that of spring 47.Thus the combination of spring 47 and back-up plate 48 constitutes a double rate spring.

ments. The intermediate abutment may be a tube (not shown) instead of the rectangular housing shown, the

tube containing the cams 25, 26 and their associated Inthe operation of the device, a stack of the material to be sorted, such'as the covers heretofore illustrated, is'placed betweenpressure plate 17 and wall l4against the side plate 4l of singulation device 40, pressure'plate 17 being pulled back manually against the tension of spring 19 to permit the insertion of the stack intothe area just described. Subatmospheric pressure, that is, vacuum, is established in conduit 13 and in the space 12 in housing 11 by the means provided for that purpose, said means being continuously operative so that it is unnecessary to provide any periodic valving in synchronism with the rotation of the cams 25 and 26. Withpressure plate 17 released, the drive for the rollers 36, 37 is rendered effective and the drive for the shaft 27 is likewise rendered effective to commence the singulation of the covers in stack 15. The foremost cover 14 will be held against the openings 34, 35 by thedifferential atmospheric pressure across the openings, and when the drive sectors 30 of the cams 25,26 strikethe foremost cover 24, the latter will be moved to the left, as viewed in FIGS. 1 and 3, through the space established by the singulation device 40 and between rollers 36 and 37. The latter then grip the cover and accelerate it in the said left hand direction, accelerating the earns 25 and 26 as well in the process. For as long as cover24 is over the openings 34 and 35, the adjacent cover 39 will not be subjected to the differential pressure between the interior and exterior of housing 11. When cover 24 is moved sufficiently to the left to uncover openings 34, 35, the previously adjacent cover 39 becomes the foremost cover of the stack and is then subjected to the differential pressure across openings 34, 35 and separated from its immediately adjacent cover. The movement of the cams 25, 26 and of the rollers 36, 37 is such that cams 25, 26 do not contact a cover in the stack until after the preceding cover has passed through the gate established by the singulation device 40.

Although in the form described above the abutment against which the foremost cover 24 bears is a flat wall 14 forming part of a substantially rectangular housing 11, it may be apparent that the desired bending effect in the foremost cover'can be achievedby other forms of abutment. All that is required is that two laterally drive as well as a connection toan evacuation device.

Other modifications of the singulation device will suggest themselves to those skilled in the art, and it is card of said stack of cards away from the card immediately adjacent the foremost card to effect a separation of a major portion of said foremost card and the card immediately adjacent thereto, and means for imparting lateral motion to the separated foremost card while restraining the immediately adjacent card from said lateral movement, said means for drawing the central region of the foremost card away from the card immediately adjacent the foremost card comprising a pair of laterally spaced abutments, means urging the stack against said abutments, a third abutment disposed between said laterally spaced abutments and in proximity to the said foremost card, an opening in said third abutment, means establishing a pressure differential across said opening, said third abutment being removed from a flat plane connecting said pair of laterally spaced abutments such that said differential in pressure causes the foremost card to be moved against the opening to assume a curved shape while said adjacent card retains a substantially flat shape.

2. A pick-off head as described in claim 1, said laterally spaced abutments comprising a substantially V flat transverse wallextending vertically across the spaced abutments be provided such as the left hand re foremost card of a stack and a vertical rib on said wall projecting outward from the surface of said wall.

3. A pick-off head as described in claim 1, and said lateral motion imparting means for the foremost card extending intermittently through said opening.

4. A pick-off head as described in claim 1, and comprising further,'means for establishing a gate slightly wider than the thickness of one card, but narrower than the thickness of two cards, through which the foremost card is driven by the lateral motion imparting means, said gate establishing means comprising a vertical abutment on the base plate disposed along the side of a stack of cards, a flat spring extending toward one of said abutments into the path of movement of a laterally moving card, and means for establishing a dual rate of deflection of said spring.

5. A pick-off head for a machine for handling singly the cards of a stack of cards, said head comprising a base plate for supporting such stack of cards on edge, means for drawing the central region of the foremost card of said stack of cards away from the card immediately adjacent the foremost card to effect a separation of a major portion of said foremost card and the card immediately adjacent thereto, and means for imparting lateral motion to the separated foremost card while restraining the immediately adjacent card from said lateral movement, and comprising further, means for establishing a gate slightly wider than the thickness of one card but narrower than the thickness of two cards, through which the foremost card is driven by the lateral motion imparting means, said gate establishing means comprising a vertical abutment on the base plate disposed along the side of a stack of cards, a fiat spring extending into the path of movement of a laterally moving card, and means for establishing a dual rate of deflection of said spring. 

1. A pick-off head for a machine for handling singly the cards of a stack of cards, said head comprising a base plate for supporting such stack of cards on edge, means for drawing the central region of the foremost card of said stack of cards away from the card immediately adjacent the foremost card to effect a separation of a major portion of said foremost card and the card immediately adjacent thereto, and means for imparting lateral motion to the separated foremost card while restraining the immediately adjacent card from said lateral movement, said means for drawing the central region of the foremost card away from the card immediately adjacent the foremost card comprising a pair of laterally spaced abutments, means urging the stack against said abutments, a third abutment disposed between said laterally spaced abutments and in proximity to the said foremost card, an opening in said third abutment, means establishing a pressure differential across said opening, said third abutment beiNg removed from a flat plane connecting said pair of laterally spaced abutments such that said differential in pressure causes the foremost card to be moved against the opening to assume a curved shape while said adjacent card retains a substantially flat shape.
 2. A pick-off head as described in claim 1, said laterally spaced abutments comprising a substantially flat transverse wall extending vertically across the foremost card of a stack and a vertical rib on said wall projecting outward from the surface of said wall.
 3. A pick-off head as described in claim 1, and said lateral motion imparting means for the foremost card extending intermittently through said opening.
 4. A pick-off head as described in claim 1, and comprising further, means for establishing a gate slightly wider than the thickness of one card, but narrower than the thickness of two cards, through which the foremost card is driven by the lateral motion imparting means, said gate establishing means comprising a vertical abutment on the base plate disposed along the side of a stack of cards, a flat spring extending toward one of said abutments into the path of movement of a laterally moving card, and means for establishing a dual rate of deflection of said spring.
 5. A pick-off head for a machine for handling singly the cards of a stack of cards, said head comprising a base plate for supporting such stack of cards on edge, means for drawing the central region of the foremost card of said stack of cards away from the card immediately adjacent the foremost card to effect a separation of a major portion of said foremost card and the card immediately adjacent thereto, and means for imparting lateral motion to the separated foremost card while restraining the immediately adjacent card from said lateral movement, and comprising further, means for establishing a gate slightly wider than the thickness of one card but narrower than the thickness of two cards, through which the foremost card is driven by the lateral motion imparting means, said gate establishing means comprising a vertical abutment on the base plate disposed along the side of a stack of cards, a flat spring extending into the path of movement of a laterally moving card, and means for establishing a dual rate of deflection of said spring. 